1. Field of the Invention
This invention relates to a pipe coupling for coupling together complimentary flexible hoses. More particularly, this invention relates to pipe couplings of the type known in the art as quick couplings and the like.
2. Information Disclosure Statement
Over the years many different types of so-called "quick couplings" have been proposed for joining together lengths of flexible hose for the conveyance of fluid material. The majority of these prior art proposals include a pair of complimentary coupling members each including an annular flexible seal removably entrapped within an annular groove defined by the coupling end of the respective members. When the respective coupling members are coupled together, the protruding ends of the annular flexible seals abut against each other to form a fluid tight seal between the respective members. One such prior art proposal is manufactured by National Equipment Corp. who produce such quick couplings under the registered trademark "NECO".
However, although the aforementioned pipe couplings provide an adequate seal for the conveyance of relatively non-abrasive fluids, problems have been experienced when such quick couplings are used for the conveyance of sand during sand-blasting operations, in that the flexible seals are exposed to the abrasive action of the sand as the sand passes through the flexible hose coupling.
The present invention overcomes the aforementioned problem by providing an abrasive resistant insert which isolates the annular flexible seal from direct contact with the stream of abrasive sand or the like.
Furthermore, in the prior art pipe couplings, the distal end of the flexible hose has customarily been secured within the bore of the pipe coupling member by providing radially drilled holes within the coupling member along the length thereof such that when the hose has been inserted within the bore of the coupling member, self-tapping screws are inserted through the radial holes to engage the distal end of the flexible hose and secure the same within the coupling member.
With such prior art means of securing the flexible hose within the pipe coupling member the pressure of the fluid being conveyed within the hose is to a large extent relied upon in order to maintain an effective seal between the distal end of the flexible pipe and the bore of the coupling member.
A need has existed in the art of a method of firmly securing and sealing the distal end of the flexible pipe within the coupling member such that the pressure within the flexible pipe caused by the passage therethrough of the fluid being conveyed is not relied upon to seal the distal end of the flexible pipe within the coupling member.
Therefore, it is the primary object of this invention to provide a pipe coupling that overcomes the aforementioned inadequacies and disadvantages of the prior art devices by providing an annular seal that is isolated from the flow path of the abrasive materials being conveyed through the pipe coupling and a method of securing and sealing the coupling member to the flexible pipe.
Another object of this invention is to provide an improved method of manufacturing a pipe coupling of the "quick coupling" type such that the pressure of the fluid being conveyed is not relied upon for maintaining a seal between the flexible pipe and the coupling member.
Another object of the present invention is the provision of a pipe coupling including a first and a second member in which the first and the second members respectively include bores and counterbores disposed such that the counterbores are of the same diameter and are aligned relative to each other when the respective coupling members are coupled together.
Another object of the present invention is the provision of a pipe coupling in which a tubular insert in disposed adjacent the respective bores of the coupling members, the insert extending between the coupling memberse to define together with the counterbores an annular space for the reception therein of an annular sealing ring.
Another object of the present invention is the provision of a method of anchoring the distal end of a flexible pipe within the third bore of a coupling member which includes accurately machining the distal end of the flexible pipe and inserting the same within the third bore of the coupling member. A flexible skirt is stretched over the second end of the coupling member such that the flexible skirt encircles, engages and is glued to the second end of the coupling member. The annular passage between the second end of the flexible skirt and the coupling member is filled with a liquid cement by pumping the liquid cement between the hose and the third bore or the liquid cement is allowed to seep under gravity between the external surface of the hose and the third bore to provide sealed engagement between the flexible hose and the coupling member. Finally the flexible skirt is released such that the second end of the flexible skirt tightly encircles the flexible hose.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Particularly with regatd to the use of the invention disclosed herein, this should not be construed as being limited to pipe couplings of the bayonet type fit and known in the art as "quick couplings" but should include couplings of any type used for coupling together flexible hose or the like.